1. Field of the Invention
The present invention relates to memory cell arrays including ferroelectric capacitors, and in particular to a passive-matrix crosspoint-type ferroelectric memory that does not include cell transistors and only uses ferroelectric capacitors.
2. Description of the Related Art
A passive-matrix memory cell array that does not include cell transistors and only uses ferroelectric capacitors has an extremely simple construction and can be produced with a high degree of integration, and therefore there is great expectation for such devices. In recent years, research and development into even higher integration has been progressing and as one example, a technique for increasing integration has been realized by stacking memory cell arrays, which are composed of ferroelectric capacitors, in a plurality of layers (see Japanese Unexamined Patent Publication No. 2002-197857 (pages 11 to 22 and FIG. 2).
To keep the adjacent memory cell arrays electrically insulated from each other when memory cell arrays composed of ferroelectric capacitors are stacked in a plurality of layers to achieve high-density integration, it is necessary to form the memory cell arrays with an interlayer insulating layer in between.
In this state, if, for example, the memory cell arrays above and below are simultaneously operated, noise will be mutually generated by the memory cell arrays that are adjacent via the interlayer insulating layer therebetween. There has also been the problem that when one of the memory cell arrays is operated, the data stored by the other memory cell array is adversely affected.
It is an object of the present invention to provide, for a crosspoint-type ferroelectric memory in which a plurality of memory cell arrays respectively composed of ferroelectric capacitors that are stacked in layers, a high-quality crosspoint-type ferroelectric memory in which memory cell arrays disposed on respective layers with interlayer insulating layers therebetween are protected against noise received from adjacent memory cell arrays.